In a conventional braider, as disclosed in Japanese Patent Application Laid-Open No.Hei6-294057, a mandrel is moved in the direction in which braids are formed, each of bobbin carriers meanders along a given track, and a plurality of yarns delivered between each bobbin carrier and the mandrel cross each other and are intertwined around the mandrel, thereby forming the braid on the mandrel.
The braider is provided with a formation stabilizing guide in front of the formation direction of the braid from a turning face of the yarn. A yarn guide ring of the formation stabilizing guide has an inner diameter corresponding to the shape of the braid to be formed, and is disposed with the ring fixed to the braider so as to be substantially parallel to the turning face of the yarn. When a braid is formed, the mandrel is moved in the formation direction of the braid while it is passed through the yarn guide ring. At the same time, a plurality of yarns are supplied from each bobbin carrier, through the yarn guide ring, to formation direction of the braid on the mandrel.
At this time, the swaying of the yarn due to the movement of the bobbin carriers, which meander along the given track, and the variation of the formation point on the mandrel, due to movement of the mandrel are restrained by the action of the yarn guide ring. As a result, the yarns to be formed cross each other regularly in the vicinity of the formation point, thereby enabling stable, uniform formation. In addition, the braids have a symmetric structure and are capable of producing a braid having proper mechanical performance.
A conventional formation stabilizing guide whose position is fixed cannot follow the mandrel's movement in a plane orthogonal to the formation direction of the braid because the guide locks the yarn guide ring in position. Such a configuration requires precise positioning between the mandrel and the guide ring. If the relative position of both the mandrel and the guide ring changes, the braid is formed imprecisely because the formation point cannot be stabilized.
In addition, an adequate action of the yarn guide ring can be achieved by disposing the mandrel so that the axis of the mandrel is nearly perpendicular to the circumference of the yarn guide ring. However, if a braid is formed using a U-shaped mandrel, transversal U-shaped mandrel, or the like, it cannot be disposed in an optimal state because the structure of the braider is restricted. For example, a braid is sometimes formed under conditions where the axis of the mandrel is diagonal to the yarn guide ring. FIG. 10 shows this configuration. In FIG. 10, m is the mandrel, G is a conventional formation stabilizing guide provided with a fixed yarn guide ring 01, Y is a yarn and C is a bobbin carrier. In this case, the formation point of the braid is not stable in the circumferential direction of the mandrel m, thereby disabling forming at a certain formation angle, and the braid thus formed has lower mechanical performance because the braid has a symmetrical structure.